Spring bearing for vacuumized electric devices



March 14, 1961 s. T. YANAGISAWA SPRING BEARING FOR VACUUMIZED ELECTRIC DEVICES Filed June 25, 1958 United States Patent() SPRING BEARING FOR VACUUMIZED ELECTRIC DEVICES Samuel T. Yanagisawa, Westport, Conn., assignor to Allis-Chalmers Manufacturing Company, Milwaukee,

This invention relates to vacuumized electrical devices and more particularly to a new and improved vacuum switch employing contact controlling means for restraining axial movement and substantially eliminating lateral movement of a movable contact.

Heretofore vacuum switches employed a plurality of sliding members for controlling the axial and lateral movement of the movable contacts. These sliding members not only are costly to manufacture but make the vacuum switch highly susceptible to shock and vibration.

In accordance with the invention claimed there is provided a new and improved electrical device such as an electric switch, a vacuum condenser, or an electron discharge device comprising in combination a vacuumized envelope, a member mounted for movement within the envelope, and a tube mounted upon the envelope and around at least a part of the member. The tube is arranged in gas tight engagement with the envelope and a cylindrically shaped bellows is xedly attached in gas tight engagement along one end thereof to the tube. The movable member is arranged to extend through the bellows -inside of the envelope and is attached in gas tight engagement to the bellows at the bellows other end. A coil spring is mounted within the tube and around the movable member to align the movable member within the tube to prevent substantial lateral movement thereof and to guide by a relatively rolling motion the movement of the movable member during actuation. lf so desired, a pair of coil springs may be utilized, one within and the other one without the vacuumized part of the envelope, to perform this same function.

It is, therefore, one object of this invention to provide a vacuumized electrical device in which a movable member is restrained in its axial movement and pre vented from substantial lateral movement.

A further object of this invention is to provide a new and improved vacuumized electrical device of the character described in which relatively rolling motion type guiding means are arranged within and without the vacuumized portion of the envelope.

A still further object of this invention is to provide a new and improved nonsliding guiding means comprising a garter type spring which restrains axial movement and substantially prevents lateral movement of a movable member in a vacuumized electrical device,

- Objects and advantages other than those set forth will be apparent from the following description when read in connection with the Aaccompanying drawing, in which:

Fig. l is an elevational view partly in axial section of a vacuum switch embodying the invention; and

Fig. 2 is a horizontal sectional view of the vacuum switch illustrated in Fig. l looking in the direction of the arrows along the line li-iL Referring more particularly to the drawing by characters of reference, Fig. 1 illustrates an electric switch 5 comprising a cylindrical envelope 6 which maybe formed, for example, of a suitable vitreous material. 4One 7'ice end of envelope 6 is provided with an annular rim 7 to which is ixedly secured in gas tight connection thereto one end of a ring or ange 8. A metallic cap 9 is sealed throughout its edge to the other end of flange 8 in the manner shown in Fig. 1. The cap 9 may be reentrant as shown or may be relatively flat or even protruding, if desired.

Base lil of cap 9 supports a contact mounting or bushing 11 to which is secured one end of a fixed contact 12. Contact 12 is arranged to extend along the longitudinal axis of envelope 6 and is substantially rigidly supported so as 4to restrict klongitudinal or lateral movement thereof. Cap 9 supports a tubular venting passage 13 through which envelope 6 is evacuated and sealed olf in the usual way.

The opposite end of envelope 6 is provided with an annular rim 14 to which is fixedly secured in a vacuum tight connection one end of a ring or flange 15. A tube or retainer 16 is sealed throughout its rim 17 to a flange ,18 on a ring like bracket 19 sealed to the tube 16 and,

in the example shown in Fig. l, is arranged to extend inwardly of envelope 6. The liared portion 19a of bracket 19 -is sealed in fluid tight connection to the other end of flange 15 in the manner shown. A metallic cylindrically shaped bellows 20 is iixedly secured in a vacuum tight connection at one end thereof to bracket 19. The other end of bellows 2li` surrounds and is fixedly attached in a vacuum tight connection to a movable contact 21 which `is arranged to extend through tube 16 into envelope 6 and in cooperating relationship with contact 12.

The relatively movable cooperating contacts 12 and 21 may be made of any suitable material such as tungsten or tungsten alloys. As shown in Fig. 1, contact 21 is arranged for longitudinal movement a limited predetermined distance by a contact actuating mechanism (not shown) while being restrained from lateral displacement. lTo accomplish this, contact 21 is supported with in tube 16 by one or more roll or coil spring guiding means such as garter springs 22 and 23. Garter springs 22 and 23 are arranged one at each end of bellows 20 within tube 16 and bracket 19 respectively and around contact 21. Each garter spring denes an aperture 24 (Fig. 2) extending through the center thereof, through which aperture contact 21 extends. The garter springs 22 and 2-3 are each snugly tted within tube 16 and bracket 19, respectively, and spring 22 snugly encircles contact 21. As shown in Fig. 1, the tube or retainer 16, which is sometimes referred to as a canister, is provided with an apertured cap 28 tixedly secured to its inner end and through the aperture of which contact 21 extends. Cap 2S serves as a means for holding garter spring 22 within tube 16 in case it has a tendency to roll out during a closing operation of vacuum switch 5. Garter spring 23 is arranged between bracket 19 and a anged cylindrical bushing 25 iixedly attached to contact 21. An apertured end cap 26 is bolted to the terminal end of vacuum switch 5 and around the movable contact 21. End cap 26 and the flanged portion of bushing 25 serve-as means for holding garter spring 23 within bracket 19.

` In order to control the arcing products emitted upon separation of the engaging surfaces of contacts 12 and 21 a cylindrical cup shaped tube or shield 27 is provided around and spaced from contact 12. Shield 27 is arranged to extend beyond the adjacent ends of the contacts so as to surround at least a part of contact 21 when in contact engaging position. Shield 27 may be formed of glass or any suitable metallic or nonmetallic material.

Upon actuation of movable contact 21 in axial contact engaging or contact disengaging direction, bellows 20 deects, allowing restricted longitudinal movement or" contact 21. The required range of movement of Conamazes tact 21 is very small. With only 716 of an inch separation between engaging surfaces of contacts 12 and 21 a current of several hundred amperes at an A.C. voltage of 15,000 may be safely interrupted and the switch can continuously conduct current up to 50 ampere's. Since normal atmospheric pressure tends to expand the bellows into envelope 6, the atmospheric pressure may be utilized to hold the contacts together in normally closed position or to speedily close the gap between them upon release of an externally applied contact separating force.

Garter springs 22 and 23 substantially prohibit lateral movement of contact 2l and in accordance with the invention claimed substantially reduce or eliminate all sl'ding parts thereby reducing or eliminating frictional wear of the moving switch pants. By snugly fitting springs 22 and 23 between contact 21 and the metallic shied 16 or bracket 19, a fixed electrical connection is formed between contact 21 and shield 16 if the end of shield lo, bracket i9 or a terminal cap (not shown) secured to flange l' serves as an electrical terminal connection.

Although the invention has been shown and described in connection with a vacuumized electric switch, it is to be understood that it may also be applied to other vacuumized electrical devices such as vacuum condensers or electric discharge devices which have movable electrodes. Such movable electrodes or other members may be supported for movement in the same manner as contact 21.

Although but ore embodiment of the present invention has been illustrated and described, it will be :pparent to those skilled in the art that various changes and Amodifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

What is claimed is:

l. In a device embodying an envelope having a member extending through an opening in one end thereof,

means for supporting said member for movement in directions inwardly and outwardly 'of said envelope cornprising an annular retainer connected in a vacuum tight seal to said envelope around said member, a bellows connected by a vacuum tight Seal to said retainer and connected by a vacuum tight seal to said member, and a roll spring mounted within said retainer in an encircling relation to said member and adapted to roll within and axial of said retainer upon movement of said member and to restrain said member from substantial lateral displacement.

2. In a device embodying an envelope having a munber extending through an opening in one end thereof, means for supporting said member for movement in d1- rections inwardly and outwardly of said envelope comprising an annular retainer connected in a vacuum tight seal to said envelope around said member, a bellows having one end connected by a vacuum tight seal to said retainer, said member extending through said bellows Vand said retainer and connected by a vacuum tight seal to the opposite end of said bellows, and a roll spring mounted within said retainer in an encircling relatonV to said member and adapted to roll within and axial of said retainer upon movement of said member and t0 restrain said member from substantial lateral displacement.

3. In a device embodying a vacuumized envelope having a member extending through an opening in one end thereof, means for supporting said member for movement in directions inwardly and outwardly of said envelope comprising an annular retainer connected in a vacuum tight seal to said envelope around said member, a bellows having one end connected by a vacuum tight seal to said retainer, said member extending through said bellows and said retainer and conncted vby a vacuum tight seal to the opposite end of said bellows, and a roll spring mounted within said retainer and within the vacuumized part of said envelope in an encircling relation to said member and adapted to roll within and t axial of said retainer upon movement of said member and to restrain said member from substantial lateral displacement.

4. In a device embodying a vacuumized envelope having a member extending through an opening in one end thereof, means for supporting said member for movement in directions inwardly and outwardly of said envelope comprising an annular retainer connected `in a vacuum tight seal to said envelope around said member, a bellows having one end connected by a vacuum tight seal to said retainer, said member extending through said bellows and said retainer and connected by a vacuum tight seal to the opposite end of said bellows, and a roll spring mounted within the said retainer and without the vacuumized part of said envelope in an encircling rela.-

tion to said member and adapted to roll within and axial of said retainer upon movement of said member and to restrain said member from substantial lateral displacement.

5. In a device embodying an envelope having a member extending through an opening in one end thereof, means for supporting said member for movement in directions inwardly and outwardly of said envelope cornprising an annular retainer extending within said envelope and connected in a vacuum tight seal to said envelope around said member, a bellows having one end connected by a vacuum tight seal to said retainer, said member extending through said bellows and said retainerand connected by a vacuum tight seal to the opposite end of said bellows, and a roll spring mounted within said retainer in an encircling relation to said member and adapted to roll within and axial of said retainer upon movement of said member and to restrain said member from substantial lateral displacement.

6. In a device embodying an envelope having` a member extending through an opening in one end thereof, means for supporting said member for movement in directions inwardly and outwardly of said envelope comprising an annular retainer extending within said envelope and connected in a vacuum tight seal to said envelope around said member, a bellows having one end connected by a vacuum tight seal to said retainer, said member extending through said bellows and said retainer and connected by a vacuum tight seal to the opposite end of said bellows, and a roll spring snugly mounted within said retainer and snugly encircling said member and adapted to roll within and axial of said retainer upon movement of said member and to restrain said member from substantial lateral displacement.

7. An electric switch comprising in combination a vacuumzed envelope, a pair ot relatively movable cooperating contacts mounted within said envelope, at least one of said contacts being axially movable'through one end of said envelope, a tube sealed by a vacuum tight joint to one end of the envelope and encircling said movable contact, a cylindrical bellows iixedly attached in gas tight connection along one end thereof to said tube, said movable contact extending through said bellows and tube into said envelope and attached in gas tight connection to the other end of said bellows, and a coil spring mounted within said tube and around said movable contact, said coil spring aligning said movable contact within Said tube and guiding by a relatively rolling motion said movable contact during actuation thereoff 8. An electric switch comprising in combination a vacuumized envelope, a pair of relatively movable cooperating contacts mountedwithin said envelope, one of said contacts being axially movable through one end of said envelope, a tube sealed to said one end of said envelope in gas tight connection therewith, a cylindrical bellows xedly attached in gas tight connection along one end thereof to said tube, said movable contact extending through said bellows and tube into said envelope and attached in gas tight connection to the other end of said bellows, coil spring means mounted within said tube and around said movable contact, said spring means aligning said movable contact within said tube and providing a relatively rolling guiding action for said movable contact during actuation thereof, and means for retaining said spring means within said tube,

9. An electric switch comprising in combination a vacuumized envelope, a pair of relatively movable cooperating contacts mounted within said envelope, one of said contacts being axially movable through one end of said envelope, a tube mounted to extend within said one end of said envelope in gas tight connection therewith, a cylindrical bellows iixedly attached in gas tight connection along one end thereof to said tube, said movable contact extending through said bellows into said envelope and attached in gas tight connection to said bellows at the other end thereof, and a garter spring snugly mounted against the inner perimeter of said tube and around said one of said contacts without the vacuumized part of said envelope, said garter spring aligning said movable contact within said tube and guiding by a relatively rolling motion said movable contact during actuation thereof, and means mounted within said switch for limiting the axial movement of said spring.

10. An electric switch comprising in combination a vacuumized envelope, a pair of relatively movable cooperating contacts mounted within said envelope, one of said contacts being axially movable through one end of said envelope, a capped tube mounted to extend within said one end of said envelope in gas tight connection therewith, a cylindrical bellows mounted within said tube and tixedly attached in gas tight connection along one end thereof to said tube, said movable contact extending through said bellows into said envelope and attached in gas tight connection to said bellows at the other end thereof, and a coil spring snugly mounted against the inner perimeter of said tube adjacent said tube cap and around said one of said contacts, said spring aligning said movable contact within said tube, guiding by a relatively rolling motion said movable contact during actuation thereof, and providing a current path from said movable contact through said tube.

11. An electric switch comprising in combination a vacuumized envelope, a pair of relatively movable cooperating contacts mounted within said envelope, one of said contacts being axially movable through one end ot said envelope, a tube mounted to extend within said one end of said envelope in gas tight connection therewith, a cylindrical bellows iixedly attached in gas tight connection along one end thereof to said tube, said movable contact extending through said bellows into said envelope and attached in gas tight connection to said bellows at the other end thereof, and a pair of coil springs snugly mounted against the inner perimeter of said tube at opposite ends of said bellows and around said movable con- 6 tact, said coil springs aligning said movable contact within said tube Iand guiding by a relatively rolling motion said movable contact during actuation thereof.

l2. An electric switch comprising in combination a vacuumized envelope, a pair of relatively movable cooperating contacts mounted within said envelope, one of said contacts being axially movable through one end of said envelope, a tube mounted to extend within said one end of said envelope in gas tight connection therewith, a cylindrical bellows iixedly attached in gas tight connection along one end thereof to said tube, said movable contact extending through said bellows into said envelope and attached in gas tight connection to said bellows at the other end thereof, and a pair of coil springs mounted within said tube and around said movable contact, said coil springs aligning said movable contact within said tube and guiding by a relatively rolling motion said movable contact during actuation thereof, one of said springs being arranged within and the other of said springs being arranged without the vacuumized part of Said envelope.

13. An electric switch comprising in combination a vacuumized envelope, a pair of relatively movable cooperating contacts mounted within said envelope, one of :said contacts being axially movable through one end of said envelope, a capped tube mounted to extend within said one end of said envelope in gas tight connection therewith, a cylindrical bellows mounted within said tube and fixedly attached in gas tight connection along one end thereof to said tube, said movable contact extending through said bellows into said envelope and vattached in gas tight connection to said bellows at the other end thereof, and Ka coil spring snugly mounted against the inner perimeter of said tube within the vacuumized part of said envelope between the cap of said tube and said bellows and around said contact, said coil spring aligning said movable contact within said tube and guiding by a relatively rolling motion said movable contact during actuation thereof.

References Cited in the tile of this patent UNITED STATES PATENTS 959,435 Thomson May 24, 1910 1,814,851 Prince July 14, 1931 2,101,346 Robertson Dec. 7, 1937 2,723,328 Verkuil Nov. 4, 1955 2,773,154 Williams Dec. 4, 1956 2,794,087 Jennings et al May 28, 1957 2,900,476 Reece Aug. 18, 1959 FOREIGN PATENTS 29,822 Great Britain Dec. 3, 1914 407,725 Germany Jan. 2, 1925 1,007,576 Germany May 2, 1957 

